Make a service class support currying, uh partial application?

foo_curry.rb

module Curryable
  def curry(arity=nil)
     method(:call).to_proc.curry(arity)
  end
end

class Foo
  include Curryable

  def call(x, y, z)
    x + y + z
  end
end


f = Foo.new
ff = f.curry.(2, 3) # or f.curry[2, 3]
ff.(4) #  or ff[4] => 9